具有宽阻带特性的四陷波超宽带滤波器

A four-notch ultra-wideband filter with wide stopband characteristics

为有效改善超宽带带通滤波器阻带较窄的问题,提出了一种基于阶梯阻抗传输线及加载两对开路短截线的矩形环多模谐振器结构。同时,在多模谐振器上采用非对称耦合线、两个嵌入式开路枝节及耦合C型枝节的方式实现四陷波超宽带(UWB)滤波器。经HFSS仿真优化后得:该UWB滤波器通带为3.62~10.66 GHz,在10.86~19.1 GHz范围内带外抑制大于20 dB。其中,实现的四陷波滤波器陷波频率发生在5.86,6.88,7.4,8.36 GHz频点处,能有效抑制WLAN、印度国家卫星通信C频段、X卫星及国际电信联盟(ITU)波段对超宽带通信系统的干扰,适用于超宽带无线通信系统。

To improve the narrow stopband of the UWB bandpass filter,a rectangular ring multimode resonator structure was proposed based on a stepped impedance transmission line and two pairs of open stubs.Meanwhile,a four-notch ultra-wideband(UWB)filter was implemented using an asymmetric coupling line,two embedded open branches,and coupling C-type branches on the multimode resonator.The simulation results using HFSS software show that the passband of the UWB filter is 3.62-10.66 GHz,and the out-of-band rejection is greater than 20 dB from 10.86 GHz to 19.1 GHz.The four notch frequencies of the filter occur at 5.86 GHz,6.88 GHz,7.4 GHz and 8.36 GHz respectively,which can effectively suppress the influence of WLAN,Indian National Satellite Communication C-band,X-band satellite and ITU band signals on UWB communication system,which is applicable to UWB wireless communication system.